This invention relates to injection molding and more particularly to heated manifold blocks which are mounted on the side of an elongated manifold to offset the nozzles relative to the manifold for injecting through several gates to a single non-linear cavity.
There is a rapidly increasing demand for the use of injection molding to make large components, particularly in the automotive industry. It is well known to connect several nozzles to a single elongated manifold to provide the considerable melt volume and short melt flow distances necessary to satisfactory fill a large cavity. In the past, these nozzles have been mounted in parallel alignment to extend forward from the forward face of the elongated manifold. While this is satisfactory for many applications, if the part is curved or otherwise substantially non-linear, it may be desirable for melt flow characteristics to locate the nozzles and gates with different orientations relative to each other. While different orientations of the various nozzles can be achieved by making the manifold with different portions of the forward face at different angles, this is not satisfactory due to melt leakage. If nozzles having different orientations are fixed to the forward face of a manifold, longitudinal thermal expansion of the manifold causes misalignment of the nozzles resulting in leakage of the pressurized melt.